A. Field of the Invention
This invention relates to fluid separation modules.
B. Prior Art
It is known to use fluid separation modules made up of a bundle of unconstrained, unsupported hollow fiber membranes positioned in a cylindrical shell. A major disadvantage of this construction is that such a module cannot be used in a horizontal position. The reason is that the fiber bundle will sag to the bottom of the cylindrical shell to leave a free space above the fiber bundle. The fluid mixture to be treated will pass primarily through this free space and will not enter the fiber bundle, such that the separation of one fluid from the mixture is very inefficient. To avoid this problem, such a module must be operated in a vertical position. This renders it much more difficult to remove the fiber bundle for inspection or replacement.
Various attempts have been made to solve this problem. For example, in the module shown in U.S. Pat. No. 4,315,819, the fiber bundle is longitudinally compacted so as to fill the shell. However, results achieved by this approach are still inferior to those obtained when the module is operated in a vertical position.
In the structure disclosed in U.S. Pat. No. 3,526,001, a number of bands encircling the fiber bundle are used in an attempt to break up flow through the fiber bundle.